Screw-propeller.



C. W. GRINDLE;

SCREW PHOPELLER.

' APPLICATION FILED Aue. x4. 1915.

mam@

Patent-ed Nov. 20, 1917.

lll/VEN TOR Zarka hf iwi/idle eran CHARLES, w. earners,orlsnairriinfwasiarive'ron, assrenon or `sonar-irrita onnrulvnnsnrrisroTranspone rter/riante,

fsoaisw-raornmrinl p mames. y

To all whom it may concern:

Be it known that I, CHARLES W. Garraum, citizen of the United States,residing at Seattle, inthe county'of King and State of I/Vashington,have invented a certain new and useful Improvement in Screw-Propellers,of which the following is a specification.

My invention relates to improvements in screw-propellers for vessels andthe object of my improvements is to provide a screwpropeller that shallbe adapted to besecurely mounted upon the outwardly projecting endportion of a vessels propeller shaft and which shall be so formed thatwhen submerged the energy transmitted to it through said shaft shall bealmost wholly expended in forcing water to move rearwardly in linesdirectly parallel with the lengthwise direction of the keel of thevessel and in forcing the vessel tomove forward in a desired course,while little of such energy shall be uselessly spent in forcing water insidewise directions at right angles to the lengthwise direction of saidkeel.

I accomplish this object by devices illustrated in the accompanyingdrawings wherein Figure 1 is a perspective View of a propeller wheelVembodying one form of my 1nvention as it appears mounted on a propellershaft; Fig. 2 is a view in end elevation of the same; Fig. 3 is a Viewof the same in vertical mid-section on broken line ai, of Fig. 2; andFig. l is a. fragmentary view in radial section of a modilied forni of adetail of the same.

Referring to the drawings, throughout.

which like reference numerals indicate like parts, 5 indicates the rearend portion of a vessels rotatable propeller shaft upon which isfastened, in a well known manner, the hub 6 of a propeller by means of anut 7 which is screwed on to the screw-threaded end 8 of the end portionof said shaft 5 to engage with the outer end surface of said hub 6 toforce said hub on to the tapered portion of said shaft 5 as more clearlyshown in Fig. 3. Y

Integral with the hub 6 are three symmetrical propeller blades 9disposed each to radiate therefrom in the form of a spiral web ofgradually increasing width, which blades 9 are equi-distant one fromanother and which extend to and are integrally united with a widecircular band 10 which is i i fSpediication of Letters Patent.alpiidatibii hidaugast ie, 1915. y seriain. 45,470.

0F SEATTLE, WASHINGTON. l

Patented Nov. 20,' 191% concentrically disposed with respectto the shaft5 to encircle said blades 9 and the hub 6 as shown more clearly in Fig.1.

Extending radially from the periphery of the band 10 are three auxiliarypropeller blades 11 .which are integral with said band 1 0 and which aredisposed thereon in spiral lines that are equi-distant one from another.d rlhe outer end portion of each of the auxiliary blades 11 is providedwith a diagonally arranged flange, as flanges l2, which flanges 12 serveto prevent water (which is being acted upon bysaid auxiliary blades 11as .they revolve) from being forced sidewise 1n a direction at rightangles to the lengthwise direction of the shaft 5; and in like mannerthe band 10 serves to force all the water which is acted upon by theblades 9 to move in a direct rearward direction, thus, no considerableportion of the energy exerted through the medium of the revolv-l ingblades 9 and l1 is wasted by uselessly moving water in sidewisedirections, but

all of such energy, less the portion that is lost by friction, isexpended in driving the Vessel forward and in forcing water to movedirectly rearward.

In Fig. 1 I have shown the blades 11 as being provided on their outerend portions with a liange 12 which projects from one side only, but inFig. 4, I have shown a fragment of a propeller, by a. View in radialsection, wherein a blade 13, which corresponds to a blade 11 of Fig. 1,is provided with anges 14 and 15 each of which project from a differentside of the blade 13, thus to adapt the propeller to be revolved ineither direcn tion with like efficient results; but in general practicethe propeller of Fig. 1 may be preferable since a vessel is seldomrequired to move in a backward direction, whereby there would be butlittle energy wasted.

IVhat I claim is:

screw propeller comprising in cornbination a hub, a plurality of spacedsymmetrical blades radiating from said hub, said blades each being inthe form of a spiral web of gradually increasing width, a wide circularband united to the wide outer edges of said blades, said band being of asingle width throughout substantially equal to the length of said huband arranged concentric therewith, an auxiliary blade coincident witheach of the tirst-nanied blades width, anda Aflange unltedto the outeredge and Vunited teitheo't'er a'cer'o'i"saidbandg'Infitniss"whereof"Iiherntolbscribe each auxiliary blade being also inthe form my name this 28th day of July, A. D. 1915. of Spiral web. ofgradually increasing ARLES GRINDLE of each auxiliary blade7 said flangesbeing, Witnesses:

' concentric with said band and arranged di FRANK WARREN,

agonally thereof. .O. y.I onmsoN. v

Copies of this patent may be obtained Vforuve cez 1teach,byggdregslngntlie Commissioner of Patents.

Washington, D'. C.

